Chapter 17: Infectious Diseases Infecting the Nervous System Flashcards
CNS consists of
- Brain
- Spinal Cord
PNS consists of
- nerves from the CNS
- sense organs and periphery of the body
Defenses of the nervous system
- Bony casings
- protect from trauma
- CSF
- provides cushioning function
- Cells that makeup blood vessels (Blood-brain barrier)
- allow only certain molecules through
- Macrophages
- have phagocytic abilities
- No microorganisms allowed
These viruses live in a dormant state in the nervous system, but are not considered resident biota
Herpes virus
Meningitis
- Inflammation of the meninges
- can be caused by a number of microorganisms and infections
Causative agents of Meningitis
- Streptococcus pneumoniae
- small, gram-positive flattened coccus
- Neisseria meningitidis
- gram-negative diplococci
- Haemophilus influenzae virus
- very acute but rare since vaccine
- Cryptococcus neoformans
- fungus
Causative agents of neonatal menigitis
- Streptococcus agalactiae
- Escheria coli
- Listeria monocytogenes
Poliomyelitis
Acute viral infection of the spinal cord hat can cause neuromuscular paralysis also known as infantile paralysis
Cause of poliomyelitis
- Small RNA viruses
- enterovirus group
- Picornavirus family (pico=small)
- highly contagious person to person and via poo
Encephalitis
- inflammation of the brain
- always a serious condition as tissues of the brain are extremely sensative to the inflammatory response
Acute Encephalitis
- almost always caused by viruses borne by insects (arboviruses)
- West Nile Virus and Herpes Virus
Herpes Simplex Virus
- Herpes simplex type 1 and 2 viruses cause
encephalitis in newborns born to HSV-positive mothers
* adults are still suseptible * Varicella-zoster virus can also cause encephilitis
Prions
- Proteinaceous infectious particles
- contain no genetic material
- causes TSE’s
transmissible spongiform encephalopathies
neurodegenerative diseases with long incubation periods but rapid progressions
Creutzfeldt-Jakob disease
a degenerative neurological disorder that is incurable and invariably fatal also called as human form of mad cow disease
Rabies
- Slow, progressive zoonotic disease
- fatal encephalitis
- fever, nausea, vomiting, headache, fatigue, and other nonspecific symptoms
How to treat rabies
wound is infused with human rabies immune globulin (HRIG)
Tetanus
Produces Tetanospasmin powerful neurotoxin and causes Neuromuscular disease also known as “lockjaw”; Neonatal tetanus
Causative agent of tetanus
- Clostridium tetani
- gram+, spore-forming bacillus
Tetanus treatment
Vaccination
Botulism
- produces exotoxin called botulinum toxin ;
- muscular paralysis, respiratory compromise leading to death.
Treatment of botulism
CDC maintains supply of antitoxin
Which of the following organisms is not a cause of meningitis?
A. Neisseria meningitidis
B. Haemophilus influenzae
C. Cryptococcus neoformans
D. Clostridium tetani
E. Listeria monocytogenes
D. Clostridium tetani
Causative agents of “Encephalitis”
- Arboviruses
- Herpes simplex virus type 1 or 2
- JC virus
